Well, I do like the principle of Less is More, I must say.
But quite why you think islands have objectively superior cultures is something of a mystery to me.
Does it matter how large the island is, for instance? (Some islands are really tiny and don't have any people on them.)
And "objectively superior" in relation to which other cultures? The only other cultures I can think of are continental ones; and I can see no reason to think that British culture (for a random example) is "superior" in any way to French or German culture (to compare countries of roughly equal sizes). Though of course it is different.
Btw I suspect you're using "objectively" here to just mean "really, really, truly, honestly". Which leads me to think that maybe you don't hail from an island culture yourself. Am I right?